Calculating device



Aug. 2, 1949. c. A. GILSON CALCULATING DEVICE Filed March 14, 1947 3mm [son Patented Aug. 2, 1949 UNITED STATES PAT ENT F FICE momma March I4, 19%, No; 734,639

This invention relates to mechanical calculating. devices and is an im-provement over Patent No. 1,404,019 dated. J anuary 17, 19221 An object of this invention. is to; provide a me.- chani-cal calculator in: the form of a disc havin arithmetic scales on the opposite faces and a pair of. pivoted arms on each face with the in.- nermostmember of each pair fixedly connected together for unitary movement, and the other member oi each pair independently adjustable to a selected. engmar position.

Another object oi this invention is, to provide a calculator oi this kind which may be formed on one face thereof. with one kin-d. of. arithmetic graduations, and may be provided. on the opposite face thereof with another kind of arithmetic graduatioms, the calculator being provided with pairs at arms movable over the scales or greduatlons, and. the scales or graduations on both sides being so correlated that the setting and adjustment of the arms on; one face of the dial will indicate the answer to another problem on; the: reverse face of the dial.

Still another object of. this invention. is to provide a calculating device of this kind having. a. pair: oi indicating arms on. both sides of a graduated disc, one arm of. each side being. fixed to one. arm. on the other side, the other arms being free to berotated. selectively independently of or together with the connected arms for transposing. calculations from one. side of the disc to the other.

Yet. another object of. this invention is to Provide a calculating, device oi the kind to be: hereinafter described, having rotatable indicating arms thereon which are so formedthat the arms contact. the disc. only near the. periphery thereof along, a space provided. for such rubbing contact whereby the rubbing o1 such arms will not rub ofi or otherwise deteriorate the indioia on the disc- A further object of this invention is to provide two indicating arms on opposite sides of. a. flat graduated dial, the arms being. so arranged that either one of the shorter arms may bemoved whilethe two long arms. remain stationary and when the long arms are moved, the short. arms are; moved the same angular distance whereby angular distance. can be added or subtracted and the result thereof may be transposed from one side of the dial to the other... By having suitable scaleson both sides of the dial, many types of problems may be quickly and accurately solved. Reierenceis had particularly to computers for use of airplane test pilots. where a. number oi correlated scales may be correlated on opposite sides 2. oi the dial, such scaleshaving, a common relatiom as based on. logarithmic progressions or other amthmeti'cscoles.

With the above and other objects in View, my invention consists in the arrangement, combination and details of construction disclosed in the drawings; and specification, and then more particularly pointed. out in the appended claims.

In the drawings,

Figure 1 is a top plan view of my calculator; and

Figure 2 is a vertical section therethrough Referring to the drawings, the numeral H1 designates generally aoalculator constructed. according to an. embodiment of my invention. The calculator to comprises: a base plate or dial. it having one or more series of scales annularly disposed thereon. As the most frequently occurring problems. in test work are those. which require calculation-s. other than simple addition. or subtraction, logarithmic scales eme the most used in multiplication and divisionproblems may be solved, so in the drawings I have shown a logarithmic scale on the dial 1 l, although other scales, including multiple logarithmicscales may be used without dig-tossing from the spirit of this in.- vention.

A bushing i2. is rotatably mounted in the center of the dial L! and scale or scales thereon. and a bolt it engages loosely through the bushing or beating L2 The bushing. i2 is so disposed that the upper edge thereoi is flush with the upper of the dial H and the lower end or the bushing l2 extends downwardly from the lower surface.

An outwardly extending radial arm [5 is carrleel by the bushmg I2 and is spaced from the disc H on the lower side by a washer or spacer to loose about the bushing H, The arm I5 is formed at its outer end with an upwardly extending detent or joggle l6 for engaging the disc H outwardly of the scales thereon whereby the arm t-isaspaced from the dial H along. its length so that continued use of this device 10 will not wear off the graduation marks on the dial H.

The arm t5 then is terminated beyond the dial H.

A similar arm H is fastened to-the bolt M- above the dial H and spacedthereahovev by a Washer to loose about the bolt M. The arm H- extendsou-twardl-y and is spaced. at its outer end from the dial II by a detent l9 extending downwardly opposite from the jogg-le: L6,. and the arm ll ex=- tends beyond. the dial H where. it is fastened to the extending arm to by bolts or rivets 20 or other suitable fastening means, and a spacer 2| is fixed between the extending portion of the arms I 5: and H, the spacer 2| being substantially the same thickness as the dial H to prevent the arms and I1 from clamping the dial l I therebetween.

A concavo-convex spring washer 22 is loose about the bolt I4 below the bushing l2, having the concave sideupward whereby the edges of the spring 22 may press upwardly against the bottom side of the lower long arm I5.

A lower bushing 24 loose about the bolt i4 is carried thereby below the bushing l2 and an outwardly extending short arm 25 is secured there on, being spaced downwardly from the spring washer 22. The arm 25 engages the lower side of the arm l5 and is terminated short of the edge of the dial 1 l with an upwardly extending detent 26 spaced from the disc ll whereby the arm 25 may be rotated over the arm [5 upon occasion.

The concavo-convex spring washer 2i, loose about the lower end of the bushing 24 presses upwardly against the arm 25, the edges of the spring 21 engaging the lower side thereof.

An upper bushing or bearing 28 loose on the bolt I4 is spaced above the arm H by a washer 29. The upper short indicating arm at extends outwardly from the bushing 28 in a manner opposite from the lower arm 25 and is formed with a detent 31 at its outer end similar to the detent 26. The spring washer 32 similar to the washerjT: is carried about the upper end of the bushing 28 and the edges of the lower concave side press the arm 3!! inwardly of the. device ID. A nut 34 on the lower end of the bolt I4 holds the assembly together and tightening the nut 34 increases the tension of the spring washers 22, 21 and 32 on their respective indicating arms;

Each of the arms is provided with a radial index line 35 which is preferably scribed on the surface of the arms which are preferably made of transparent plastic material so the graduation on the metal disc I I may be readily viewed therethrough.

By the arrangement as above described, the short arms 25 and are free to turn about the pin or bolt l4 independently of each other and independently of the long arms I5 and I! whereas movement of the connected arms I5 and I! efiects a corresponding angular movement of the arms 25 and 30 from their independently selected position relative to the arms l5 and i1.

Using a logarithmic scale on the dial l l, multi plication problems are readily solved on either or both sides of the dial by the proper movement of the arms.

A typical multiplication problem is indicated in Figure 1, the object being to multiply 5 x16. The long arms I! and 15 are positioned so that the index line registers with the multiplier 5, and one short arm as 36 is placed so the index line 35 registers with the index or mark ID on the log scale, as shown in full lines. The long arm I?! is then rotated until the index 35 of the arm 33 registers with the multiplicant !6, thereby rotating the short arms 33 and H a like angular distance about the scale, whereby the index 35 on the long arm I! will indicate the product, or 80, shown in dotted lines. Division is performed in the reverse manner, similar to conventional slide rule procedure, as proportions and other slide rule calculations.

However, as in aircraft flight calculations, several products are desired nearly simultaneously by the pilot or navigator and a similar multiplier is used for both problems. By using a device of this kind both products may be found with but a single movement. As an example, fuel consumption for a definite period of time and distance over the ground towards a base. Using round numbers for convenience, after 5 hours of flight in a plane burning 60 gallons of fuel an hour and travelling at a ground speed of 120 miles per hour, the pilot can determine the total gas consumption and distance by a single movement of the device. The arms I! and I5 are set with the lines 35 registering with the index I0 on both the upper and lower scales. For calculating fuel consumption on the upper scale, the short arm index line in registry with the mark I2.

39 is placed with its index line over the mark 58, and for determining the distance covered on the lower scale, the short arm 25 is placed with its Then by rotating the long connected arms l5 and ll until the index line registers with the numeral 5 on both the upper and lower scales, at the same time, both products are indicated by the short arms 30 and 25 respectively, each moving a similar angular distance, about 107 degrees, so that the arm 30 indicates 300 gallons of fuel consumed, and the arm 25 indicates 600 miles, distance covered. Similar'correlated problems may be solved in much the same manner simultaneously, thus reducing considerably the time and eiTort required by previous slide rule arrangements, such rapid calculating means being of considerable aid in the present high speed airplanes wherein seconds lost in calculations result in excessive loss of fuel'and distance when a correction or change of the flight must be made as a result of such calculations.

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claims.

What I claim is:

l. A calculating device of the kind described comprising an annular flat dial having circular scales thereon, a central bushing loose in the center of said dial, a bolt rotatable in said bushing, a pair of indicating arms on opposite sides of said dial extending radially beyond the periph eral edge thereof, means connecting said arms together beyond said dial, one of said arms being fixed to said bushing, the other of said arms being fixed to said bolt, a washer spacing said arms from said dial at the center thereof, a pair of bushings on said bolt on opposite sides of said central bushing, a second pair of indicating arms, each .of said latter arms fixed to one of said latter bushings, a washer between one of said latter bushings and said central bushing, a concavoconvex spring washer between the other of said latter bushings and said central bushing fric tionally biasing one of said first pair of arms in engagement with said dial, and a pair of outer concavo-convex spring washers about said latter bushings biasing said latter pair of arms in engagement with said first pair .of arms whereby all of said arms may be rotated simultaneously relative to said dial.

2. A calculating device of the kind described comprising an annular flat dial having circular scales thereon, a central bushing loose in the center of said dial, a bolt rotatable in said bushing, a pair of indicating arms on opposite sides of said dial extending radially beyond the peripheral edge thereof, means connecting said arms together beyond said dial, one of said arms being fixed to said bushing, the other of said arms being fixed to said bolt, a washer spacing said arms from said dial at the center thereof, a pair of bushings on said bolt on opposite sides of said central bushing, a second pair of indicating arms, each of said latter arms fixed to one of said latter bushings, a washer between one of said latter bushings and said central bushing, a concavoconvex spring washer between the other of said latter bushings and said central bushing frictionally biasing ,one of said first pair of arms in engagement with said dial, a pair of outer concavo-convex spring washers about said latter bushings biasing said latter pair of arms in engagement with said first pair of arms whereby all of said arms may be rotated simultaneously REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,042,360 Maguire Oct. 22, 1912 1,404,019 Gilson Jan. 1'7, 1922 1,868,816 Dempster July 26, 1932 

